Abstract: The hardware and software electrocircuit of radar feed location instrument were designed by using triangular wave modulation. They were switched capacity filter chip based on the principle of linear frequencymodulation continuous wave feed location instrument, and the performance of the designed instrument was also tested. The test results indicated that this instrument could accurately measure the height of materials in the distance of 2 to 40 m, and the relative error was less than 1%. This system has the character of low price and high accuracy.